Pulsed laser radiation is used in the refractive laser treatment of a human eye, for example for making cuts in the cornea or for the ablation of corneal tissue (i.e., for removing tissue from the corneal surface). The irradiated laser radiation causes a photodisruptive process in the corneal tissue, which results in tissue separation or vaporization of tissue. Within the scope of such treatment of the cornea, the corneal surface is re-formed, thus altering the refractive property of the cornea in order to reduce or completely eliminate vision defects of the eye.
Test applications are typically carried out prior to the actual laser treatment of the human eye. In this case, the laser radiation is applied to a test object according to an example application profile. Such test applications are used, for example, for calibrating the laser device used for the laser treatment, such as for calibrating the energy of the laser radiation that is emitted by the laser device. For testing the ablation caused by the laser radiation, the laser radiation is conventionally directed onto photographic paper, and the material removal which occurred on the photographic paper is determined.
In the course of a laser treatment, the eye to be treated typically moves translationally and rotationally in multiple dimensions. Eye tracking systems (so-called eye trackers) having at least one infrared camera are used to record infrared images of the eye, and by means of suitable processing software, to detect from the recorded infrared images the movement of the eye in the course of treatment.
To simulate the application of the laser radiation which is adapted to the eye movement of a patient, the test objects have eye structures, for example an eye pupil and an iris structure, which are detectable using the eye tracking system. These types of test objects are conventionally realized as sheet- or plate-shaped objects having an imprinted replica of at least one of the eye structures. However, within the scope of test applications, all degrees of freedom of the eye movement which are possible in the course of treatment, for example a rotational eye movement, cannot be adequately simulated using the described test objects.